DevTools: rename debugger/ to devtools/, move DevTools files into content/renderer/devtools.

content/browser/debugger/manual_tests/dom-mutation.html

-<script>
-function test1() {
-    document.getElementById("test").src = "resources/mutate-frame.html";
-}
-
-function test2() {
-    document.getElementById("test").src = "resources/mutate-frame-2.html";
-}
-
-var count = 1;
-function run() {
-    var container = document.getElementById("test2");
-    var div = document.createElement("div");
-    div.textContent = "Testing " + (count++);
-    container.appendChild(div);
-    if (count > 10)
-        container.removeChild(container.firstChild);
-}
-
-setInterval(run, 1000);
-</script>
-<p>To begin test, open DevTools, Elements Panel and watch the DOM change to match the page.
-Clicking the buttons will navigate the subframe, and the all the subframe child nodes should change.
-Expand DOM nodes in the Elements Panel to see new nodes appearing in the list live.</p>
-<div style="clear: both">
-<button onclick="test1()">Test Frame 1</button>
-<button onclick="test2()">Test Frame 2</button>
-</div>
-<div style="float: left">
-<iframe id="test" src="resources/mutate-frame.html" width="200" height="300"></iframe>
-</div>
-<div style="float: left; margin-left: 10px;" id="test2"></div>